A method of treating a living organism to achieve a heart load reduction, and apparatus for carrying out the method.
The present invention relates to a method of treating a mammal or other living organism having a heart and a peripheral vascular system, in particular a human being to achieve a heart load reduction and a whole variety of other treatments and associated benefits as well as to an apparatus for carrying out the method.
To assist an understanding of the invention it is first necessary to consider the working of the human heart and the known prior art in this field.
The condition of the human heart is frequently measured by means of an electrocardiogram, the typical output trace that is obtained can, for example, be seen from FIG. 1. An electrocardiogram is basically a record of the sequence of electrical waves generated at each heart beat and the different peaks of the typical electrocardiogram are usually designated by the letters P, Q, R, S and T. The so-called R-R path, i.e. the time between two R peaks represents one cycle of the heart and normally amounts to about 1 second.
Of particular interest is not only the R-R path which corresponds to the frequency of the heart or the pulse rate, but rather also the Q-T path which reproduces the working performance of the heart, called the systole. The remainder of the path equivalent to R-R minus Q-T. i.e. T-Q effectively represents the recovery time of the heart in each heart beat, called the diastole. The operation of the human heart is discussed later in more detail with reference to FIGS. 1A, 1B and 1C.
Cardiologists frequently refer to the concept of the heart load which is proportional to the heart pulse rate, i.e. the frequency of R-R waves measured in heart beats per minute, multiplied by the systolic blood pressure as measured in millimeters of mercury.
Many treatments have been proposed and used in the prior art which affect the cardiovascular system of human beings. Well known amongst such systems are electrophysiological methods and apparatus which, for example, use electrical stimulation to produce muscle contractions which result in working and training of the muscles. The contractions and elongations caused by electrical stimulation improve the blood flow through the muscles and improve the muscle quality without effort on the part of the patient being treated.
Electrophysiological interactions with living bodies in general, and human beings in particular, can be classified into two main groups, namely asynchronous and cardiosynchronized electrophysiological interactions.
Asynchronous electrophysiological methods and apparatus operate using electrostimulation in which the stimulation is timed in accordance with some externally imposed rhythm, but this timing is not synchronized with the heart pulse rate. Known examples of asynchronous electrophysiological methods and apparatus include:
neurostimulation and neuromuscular and direct muscular stimulation by electrostimulators, with equipment being available from Medicompex SA, Valmed SA, Nemectron GmbH, and EMPI Inc. among others,
the use of electrostimulation for the therapy of pain, with equipment being available from Medtronic Inc. among others,
electrostimulation for active tremor control therapy, for which Medtronic Inc. among others supplies equipment and
electrostimulation for urinary control, again with apparatus being offered by, for example, Medtronic Inc., such as that company""s Interstim product.
All the above asynchronous stimulation methods certainly bring benefits to the areas being treated, but result in an increase of the heart load when compared to a normal situation, i.e. without electrostimulation. This heart loading is even known to include an inherent risk of producing arrhythmia or heart problems, when the electrostimulation is applied near the heart on the chest muscle and especially on the left hemithorax.
A useful summary of electrical stimulation therapy is to be found on pages 3 and 4 of the xe2x80x9cUsers Manualxe2x80x9d produced by Valmed SA in relation to their Microstim (registered trade mark), neuromuscular stimulator P4 Physio Model, issue November 1996.
The other basic category of electrophysiological techniques, namely cardiosynchronized electrophysiological methods and apparatus, comprise methods by which the heart pulse rate is predetermined by means of a sensor and stimulation is delivered in a rhythm at any time within the heart pulse rate and is synchronized with the heart pulse rate.
Such cardiosynchronized methods and apparatus can be subdivided into two classes, namely the simpulsation mode and the counterpulsation mode.
In the simpulsation mode of a cardiosynchronized electrostimulation of muscles the electric impulses are synchronized with the heart pulse rate so that the heart and the stimulated muscle are contracting at the same time, i.e. in systole phase the heart is contracting and the stimulated muscle is contracting. In the diastole phase the heart is relaxing and the muscle is relaxing.
In the counterpulsation mode of a cardiosynchronized electrostimulation of muscles the electric impulses are timed in such a way relative to the heart pulse rate, that the heart and the stimulated muscle are contracting in opposition to each other, i.e. in the systole phase the heart is contracting and the stimulated muscle is relaxing, in the diastole phase the heart is relaxing and the stimulated muscle is contracting.
Known examples of such cardiosynchronized electrophysiological methods/equipment include:
Cardiosynchronized pacemakers, anti-tachycardia pacemakers and defibrillators, which are, for example, again available from Medtronic Inc.,
Cardiomyostimulators, also available from Medtronic Inc., Intra-aortal balloon counterpulsation methods and apparatus,
Cardiomyoplasty surgery for heart muscle conglomerates assisted by cardiosynchronized electrostimulation,
External aorta counterpulsation method in which the aorta is bound by a musculo-aponeurotical graft, with its free end bissected to mobilize a sector of the aorta, as disclosed in the patent, SU 1509045 A and in the English language paper by L. V. Lapanashvili, entitled xe2x80x9cAutomuscolar System of Assisted Circulation for Surgical Correction of Cardiac Failurexe2x80x9d, published in xe2x80x9cIl Cuorexe2x80x9d, Rivista di Cardiochirurgia e Cardiologia, Vol. IX, n. 1 January/February 1992, pages 5 to 27.
Pacemakers and defibrillators are well known and are inserted into the patient""s body by a surgical operation. They also require replacement at regular intervals. This class of device is therefore an invasive surgical technique and indeed stimulates the heart muscles directly and does not act on the peripheral vascular system.
A cardiomyostimulator operates by taking a signal from the heart and using it to stimulate another muscle in synchronism with the heart beat.
The surgical technique used in conjunction with a cardiomyostimulator is referred to as cardiomyoplasty and is, for example, described in the book xe2x80x9cTransformed Muscle for Cardiac Assist and Repairxe2x80x9d edited by Ray C. J. Chiu, Ivan M. Bourgeois, Bakken Research Center Series, Volume 2, Chapter 21, pages 231 to 233.
The cardiomyoplasty procedure consists of wrapping a skeletal muscle around the heart and stimulating this wrapped around muscle in a manner synchronized with the heart contractions, i.e. in the simpulsation mode, thereby forming a heart muscle conglomerate which assists the heart pumping function. By way of example a cardiomyostimulator supplied by Medtronic Inc., as model SP1005, is a two-channel system consisting of a cardiac pacemaker channel and a myostimulation channel coordinated by a synchronization circuit. The cardiac pacemaker consists of a sensing amplifier, which monitors the intrinsic heart rate and an output stage, which paces the heart as soon as the heart rate drops below a programmed value. A cardiac event can be sensed or initiated by the device, as in a synchronized pacemaker, but furthermore it also triggers the synchronization circuit. The trigger signals are processed through a programmable divider, which allows for different heart/wrapped around muscle contraction ratios within the heart muscle conglomerate. A delay is then initiated after which the myostimulator is enabled. This sends a burst of impulses, beginning typically at the end of the R-wave and ending typically at the end of the T-wave, to the wrapped around muscle via a pair of muscular pacing leads resulting in the heart muscle conglomerate contracting in the simpulsation mode. As the name implies, cardiomyoplasty surgery is used to improve heart muscle conglomerates and is also an invasive method.
The intra-aortal balloon counterpulsation is a high-risk, complicated invasive surgical technique which is only used with terminally ill patients. It involves the insertion of a balloon into the aorta which is pumped up and evacuated in accordance with the heart rhythm so that, when inflated, the balloon generates a back-pressure wave improving blood flow through the coronary blood vessels and thus increasing the oxygen supply to the heart and hopefully improving its condition.
The external aorta counterpulsation process is also a form of myoplasty surgery and uses cardiosynchronized electrostimulation of skeletal muscles wrapped around the aorta and, when operated in the counterpulsation mode, results in an increase of coronary blood circulation in the diastolic phase, with a consequential decrease of the heart load. The above mentioned paper by Lapanashvili L. V. in xe2x80x9cIl Cuorexe2x80x9d, reports on a 28% increase of coronary blood circulation. However, it will be understood that this is a serious invasive surgical operation only used in critical cases and therefore of limited application.
All of the above cardiosynchronized electrophysiological methods which use stimulation in the simpulsation mode do not result in a significant change of the heart load when compared with the heart load of the same person without stimulation. The counterpulsation methods hitherto described all involve invasive surgery. There are, however, some further counterpulsation methods referred to in the literature which are essentially non-invasive and these are based on so-called pneumatic boot therapies.
Such pneumatic boots or compression boots, for example the boot made by the Circulator Boot Corporation, do not use electrostimulation, but instead apply pressure pulsations pneumatically to the lower leg of the patient. More specifically this equipment applies pneumatic compression to the patient""s lower leg and this application of pressure is synchronized with the heart rhythm. The Circular Boot product is known to be a non-invasive cardiosynchronized pneumatic compression boot which pneumatically compresses chosen portions of body extremities, for example the lower leg, in either the simpulsation or counterpulsation mode. In the latter mode the Circulator Boot is timed to release the leg in anticipation of the cardiac systole and the primary intention is to improve arterial flow in the leg.
Indications for which the Circulator Boot can provide treatment are poor arterial flow in the leg, diabetes, arterial insufficiencies, venous diseases, lymphedema, etc.
It is stated by the manufacturers, on their home page as of Jun. 29, 1999, that Circulator Boot therapy increases stroke volume by decreasing afterload while at the same time decreasing heart work and maintaining or increasing coronary perfusion. The fact that the Circulator Boot has some effect on the heart can be seen from the statements on the cited home page, where it is, for example, stated that xe2x80x9canecdotal measurements providing evidence for cardiac benefit have included: reduction of the loudness of mitral insufficiency murmurs; widening of the peripheral pulse tracing with leg pumping during systole; narrowing of the tracing with end-diastolic pumping; raising the dicrotic notch with systolic pumping and lowering it with end-diastolic pumping and, in patients with a Swann-Ganz catheter in place, lowering wedge pressure and increasing cardiac outputxe2x80x9d.
Finally, reference is made to the Georgian patent 366 of the present inventor L. V. Lapanashvili which describes the stimulation of muscles in a non-invasive external technique in the simpulsation and counterpulsation mode. This document discusses stimulation of muscles on the chest, near the heart, in the simpulsation mode and states that xe2x80x9cit unloads the heart and enables even chest muscles located near the heart to be stimulatedxe2x80x9d. Thus, here, heart unloading has been achieved by stimulating the chest muscle in the simpulsation mode. The patent states that the regime of counterpulsation is most often used, but when electrodes are placed on the chest, i.e. near the heart, the regime of simpulsation is used.
A principal object of the present invention is to provide an almost universally applicable method and apparatus by which a substantial degree of heart unloading can be achieved by appropriate non-invasive or invasive stimulation of the patient which can be applied without practical time limitation and in particular without any restrictions of the muscles to be stimulated, with the exception of the heart muscle itself.
Moreover it is an object of the present invention to provide a method and apparatus which is entirely harmless and which can be used not only for the prevention and rehabilitation of coronary infarct and heart insufficiency, but also for neuromuscular or direct muscle stimulation, resulting in visible or non-visible muscle contractions, for muscle power or endurance development, body shaping, lypolysis treatment and the like.
It is a further object of the present invention to provide a method and apparatus capable of use for neuro- neuromusclar or direct muscular anti-pain stimulation including trancutaneous electrical nerve stimulation (frequently called TENS) as well as for many other applications of aesthetic and curative medicine.
In order to satisfy this object there is provided, in accordance with the invention, a method of treating a mammal or other living organism having a heart and a peripheral vascular system, in particular a mammal, and especially a human being, to achieve a heart load reduction, said organism having a pulse rate and a systolic pressure resulting from the action of the heart, the method comprising the steps of:
measuring the heart rhythm,
producing pressure pulsations in the peripheral vascular system by a non-invasive method in synchronization with the heart rhythm in the counterpulsation mode and
varying at least one parameter of said pressure pulsations to produce an optimized reduction of at least one of said pulse rate and said systolic pressure and hereby a net reduction in said heart load, said heart load being a function of said pulse rate and said systolic pressure.
A corresponding apparatus for carrying out the method comprises means for measuring the heart rhythm, means for producing pressure pulsations in the peripheral vascular system by a non-invasive or invasive method in synchronization with the heart rhythm in the counterpulsation mode and means for varying at least one parameter of such pressure pulsations to produce an optimized reduction of at least one of said pulse rate and said systolic pressure and hereby a net reduction in said heart load.
The invention is based on the wholly surprising discovery that it is possible, by optimizing the pressure pulsations produced in the peripheral vascular system of a patient by a non-invasive method in synchronization with the heart rhythm in the counterpulsation mode, to secure an optimized reduction in the patient""s pulse rate and hereby a significant, and indeed highly significant, net reduction in the heart load. This is a particularly surprising discovery because it is not at all evident that a totally non-invasive stimulation of, for example, a leg muscle, on only one of the many peripheral branches of the cardiovascular tree would ever be able to increase coronary blood flow and reduce heart load by a significant amount. Indeed it is totally surprising that the degree of reduction of the heart load achieved in tests is similar to that achieved by the risky, fully invasive, extra-aortal muscular flap wrapped around the aorta assisted by electrostimulation. It will be appreciated that these latter techniques act directly at a location on the aorta, the main trunk of the cardiovascular tree, whereas the invention acts externally on just one of many branches of the peripheral vascular system.
More specifically it has been found that, by correctly setting the pressure pulsations for the individual patient, a type of resonant phenomena arises which can be exploited, so that a small perturbation of the peripheral vascular system leads to an optimized reduction in the pulse rate and through this a net reduction in the heart load. It is particularly favorable that the reduction in the pulse rate is also accompanied by a reduction in the systolic pressure so that a very pronounced effect with respect to the heart load is achieved by just a small perturbation of only one peripheral branch of the cardiovascular tree. With patients having normal blood pressure there is only a small reduction in blood pressure, but a large reduction in pulse rate. For patients with high blood pressure the reduction in blood pressure is pronounced, but the reduction in heart rate less so. The method and apparatus of the invention can namely be used for the simulation of any smooth or skeletal muscle in the body, other than the heart muscle, and will result in the beneficial effect of significant heart unloading as described above.
Looked at another way, the method of the invention is a method of achieving a heart load reduction in a living body having a heart, such as a mammal, and especially a human being, by measuring the heart rhythm and by producing pressure pulsations in the peripheral vascular system in synchronization with the heart rhythm in the counterpulsation mode to produce an optimized reduction in the pulse rate and hereby a net reduction in the heart load, the heart load being a function of the pulse rate and the systolic pressure.
In distinction to a pneumatic boot, the apparatus of the present invention can be made extremely light, compact and portable and can be worn by the user in the course of normal daily life without any significant restrictions on the patient""s mobility and style of living. The means for measuring the heart rhythm can easily comprise a non-invasive sensor at some discrete position on the patient""s body, since the sensor only needs to provide a basic signal enabling synchronization of the stimulation apparatus in the counterpulsation mode.
To ensure the mobility of the patient, this stimulation apparatus is conveniently an electrostimulation apparatus which can be powered by a small battery carried by the patient. The energy requirement is not excessively high because, as noted above, the apparatus basically only imposes a perturbation on the peripheral vascular system of the patient and the effect of this perturbation is effectively enhanced by a phenomenon which is not understood in full, but which can be likened to resonant phenomenon where a small perturbation results in a large effect. For this reason the method of the invention can be referred to as a cardioresonance stimulation method and apparatus.
In addition to electrical stimulation the present invention can, however, also be realized by using other ways of producing pressure pulsations in the peripheral vascular system, such as the use of a pressure pad contacting or encircling any skeletal or smooth muscle of the organism belonging to the peripheral vascular system. Although a pneumatic boot could be used for this purpose, it is also possible to use a much smaller simple pressure pad in order to realize the present invention because the function of the pneumatic stimulation is simply to produce a small perturbation in the peripheral vascular system rather than to squeeze the whole lower leg to effectively pump blood through it.
Accordingly, a pneumatic or hydraulic pressure pad for use in accordance with the invention can be made small and light and thus used during the normal daily life of the patient, rather than only being capable of being used when the patient is at rest, this being a serious disadvantage of a pneumatic boot, particularly since it restricts the length of each treatment. In contrast the apparatus of the present invention can be used for days on end if desired.
Other ways of producing pressure fluctuations in the peripheral vascular system can comprise treating the patient by impulses of light or by means of a pulsating oxygen supply, or indeed a pulsating CO2 supply. Laser excitement treatments, electrically energized acupuncture treatments and acoustic treatments can also be considered as ways of producing the required pressure pulsations in the peripheral vascular system. In each case it is important that the stimulation is applied in a counterpulsation mode and that the parameters of the stimulation are appropriately selected for the patient, such parameters comprising:
the impulse delay before the start of counterpulsation, said impulse delay being the time difference between the Q-wave end of a QRS heart rhythm signal and the start of a train of stimulating impulses generating pressure pulsation,
the train duration, i.e. the time between the start and end of a train of stimulating impulses within one heart rhythm,
the frequency of the impulses forming a train of stimulating impulses generating pressure pulsation,
the impulse width, i.e. the time between the start and the end of one stimulating impulse of each said train,
the amplitude of stimulating impulses generating pressure pulsation,
the impulse form, being the geometric form of the stimulating impulse resulting when an amplitude of the impulse is displayed over a full impulse duration,
the impulse mode, being the relationship between positive and negative half cycles of each said stimulating impulse.
The method of the present invention can also be used in conjunction with a long term ECG, for example a 12-channel ECG, enabling medical practitioners to obtain a detailed insight into the patient""s response to the treatment over a longer period of time. Such long-term ECGs, again in the form of portable apparatus are known per se and usually involve the temporary storage of data, a facility for compression of the stored data and a facility for read-out at regular intervals, for example once per day.
The cardioresonance electrostimulation method of the invention results in accompanying effects in all body systems influenced by dynamic changes in the cardiovascular system. I.e., on using the invention it is found that reactions result in all body systems of the living body, which are triggered by dynamic changes in the cardiovascular system by the cardioresonance phenomena resulting from the use of the invention.
The reactions in these other body systems can not yet be fully explained, however results have been observed in various body systems and these body systems are well known to be influenced by dynamic changes in the cardiovascular system. Some of the observed results are measured facts, some of them are perceptions and feelings reported by the probates. However, these observed results allow the assumption, that similar physical/physiological/biochemical reactions take place in these systems interlinked with the cardiovascular system. These observed results include observations which are partially known from asynchronous electrostimulation, however, with cardioresonance electrostimulation these reactions are more pronounced due to the cardioresonance phenomena.
The observed improvements include:
increased muscular endurance, power and mass
intensified regional lipolysis by increased metabolism
reduction of pain in body support and motion system (bone, nerves and muscles working together) e.g. by strengthening of selective leg muscles and thereby unloading knee joints by changing the loading angle, whereby the loading force in joints are applied to other areas, resulting in reduction of pain caused, for example, by arthrosis, or by osteochondrosis whereby strengthening of selective back muscles will reduce pain caused by backache or radiculitis and ischiasis
improved quality of skin, becoming smooth and elastic by increased regional blood circulation
increased immunological resistance, e.g. reduction and elimination of chronic inflammation was measured
improved mental and psychological condition, e.g. cheerfulness, mood improvement by increased endorphin production etc.
normalization of sleep
increased overall fitness, wellness and working capabilities and efficiency
feeling light when walking, etc.
A particularly important aspect of the present invention is the way the time, i.e. the impulse delay, at which stimulation is applied to the living organism by the input system is adjusted to compensate for the reduction in pulse rate resulting from the treatment which has been found to enhance the cardioresonance phenomenon underlying the present invention.
It should be noted that it is, however, conceivable that the invention can be realized without this adjustment. For example, the time, i.e. the impulse delay, at which the stimulating impulses are applied to the living organism or patient could initially be delayed beyond the end of each T-wave, so that as the patient""s heart rate drops as a result of the stimulation and the end of the T-wave occurs later, due to the increased duration of each heart beat, the stimulating impulses ultimately coincide with the end of the T-wave at the lower heart beat.
There are two basic ways in which the end of the T-wave can be established from the point of view of triggering each new train of stimulating impulses. In the first case the end of the T-wave can be directly detected, for example, from an electrocardiogram and the trains of pulses triggered as soon as the end of the T-wave has been detected.
Alternatively, other reference points on the electrocardiogram can be recognized, for example the ends of the Q-waves or the R-peaks, and a suitable delay to the end of each respective T-wave can then be calculated, since the length of the Q-T path has a known fixed relationship to the length of the R-R path. The trains of stimulating impulses are then triggered at the calculated ends of the T-waves.
The duration of each train of stimulating impulses is preferably selected to amount to 10 to 25% of a T-Q diastole duration, for example of the T-Q diastole duration of a normal human being at rest. Although the trains of pulses are preferably triggered precisely at the end of each T-wave, it is believed that this triggering point can be varied within the range from 5% of the Q-T systole duration before the end of the T-wave to 10% of the Q-T systole duration after the end of the T-wave.